Top frame assembly

ABSTRACT

A top frame assembly having an upper member having a central opening defined therethrough and a generally planar upper wall, a first plurality of ribs extending downwardly therefrom, and a first mating surface. Also included is a bottom member having a central opening defined therethrough and a generally planar lower wall, a second plurality of ribs extending upwardly therefrom, and a second mating surface, wherein the first and second mating surfaces are attached to each other. Also included is at least one insert member disposed between the upper wall and the lower wall.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of co-pending application Ser.No. 09/576,163 filed on May 22, 2000.

TECHNICAL FIELD

[0002] The present invention relates to a top frame assembly.

BACKGROUND ART

[0003] A top frame is typically used in conjunction with a pallet forthe mass shipping of objects. The top frame is placed on top of a loadto stabilize the load for shipment. The top frame is typically used inconjunction with a pallet which is positioned at the bottom of the sameshipment. Until recently, top frames were made of wood. However, recenttop frames have been molded in plastic. U.S. Pat. No. 5,160,029 byPigott et al. discloses a plastic top frame used in association withpalletized goods. The top frame is subject to stress and torsionalforces, and other types of load, such as those forces placed upon thetop frame by strap (S). This top frame use a series of open rib forreinforcement. However, over a period of extended use, the structure ofthis top frame may not have sufficient strength and may tend to deformor fracture under such stress and bending

[0004] Accordingly, an improved top frame is desired which is able towithstand a relatively high amount of load, stress, torsional forces,and bending to which a top frame is subjected.

DISCLOSURE OF INVENTION

[0005] It is an object according to the present invention to provide atop frame which is able to withstand a relatively high amount of stressand torsional forces.

[0006] It is another object according to the present invention toprovide a top frame assembly which has at least one insert member forproviding strength and reinforcement to the top frame assembly.

[0007] It is yet another object according to the present invention toprovide a top frame assembly which receives an insert member forproviding strength and reinforcement to the top frame assembly.

[0008] In keeping with the objects and goals according to the presentinvention, an improved top frame assembly is provided which includes aframe portion which defines a receiving compartment therein, and atleast one insert member, but preferably a plurality of insert members,which is disposed within the compartment of the frame for providingstrength thereto. The insert member is preferably metal. The frame mayhave generally rectangular perimeter, wherein the at least one insertmember extends along at least one side of the generally rectangularperimeter. In another embodiment, the frame may include a pair of planarmembers having a plurality of rib members extending therebetween. Theframe may also include a top member and a bottom member, where the topmember has an upper surface and a first opposed mating surface, and thebottom member has a lower surface and a second opposed mating surface,where the first and second opposed mating surfaces are welded together.

[0009] Another embodiment of top frame assembly includes a top memberwhich has a top surface and a first mating surface, a bottom memberwhich has a bottom surface and a second mating surface which correspondsto and mates with the first planar mating surface. Also included is atleast one insert member disposed between the first and second matingsurfaces for enhancing the strength of the top frame assembly. Theinsert member is preferably a metallic insert and includes a planarportion. In this embodiment, the top member may have a first pair ofopposed side members including the first mating surface, and the bottommember has a corresponding second pair of opposed side members whichincludes the second mating surface, such that the at least one member isa pair of inserts each of which is disposed between a respective firstand second pair of opposed side members. The top surface and bottomsurface preferably are each planar and oriented parallel to each other,and the first and second mating surfaces may be defined by correspondingcross-rib patterns. In such an embodiment, the first and second planarmating surfaces are attached to each other such that the correspondingcross-rib patterns define a plurality of whole box beam sectionsextending across the top frame assembly.

[0010] This embodiment may also include a top member which has agenerally rectangular upper perimeter member which includes the firstmating surface, and a bottom member which has a generally rectangularlower perimeter member which corresponds to the upper perimeter member,and wherein the lower perimeter member includes the second matingsurface.

[0011] In still another embodiment according to the present invention, atop frame assembly is provided which includes a first planar memberhaving a first mating surface, a second planar member having a secondmating surface for attaching to the first mating surface, wherein one ofthe first and second mating surfaces is defined by a rib pattern, whichmay also include a cross-rib pattern. Also included is at least oneinsert disposed between the first planar member and the second planarmember to enhance the strength of the top frame assembly. The insert ispreferably a metallic insert. In this embodiment, the first planarmember may include a first pair of opposed side members which includesthe first mating surface, and the second planar member which has acorresponding second pair of opposed side members including the secondmating surface, such that the insert is a pair of inserts each of whichis disposed between a respective first and second pair of opposed sidemembers.

[0012] Further, in this embodiment, the first planar member may have afirst outer surface and the second planar member has a second outersurface, such that the first and second outer surfaces are orientedparallel to each other. The first and second planar mating surfaces areattached to each other such that the rib pattern define a plurality ofwhole box beam sections extending across the top frame assembly. The topmember may have a generally rectangular upper perimeter member whichincludes the first mating surface, and the bottom member may have agenerally rectangular lower perimeter member which corresponds to theupper perimeter member, so that the lower perimeter member includes thesecond mating surface.

[0013] In still another embodiment according to the present invention,provided is a top frame assembly which has a pair of opposed sidemembers and also includes a top member having a top pair of opposed sideportions, a bottom member which is mounted to the top member and has abottom pair of opposed side portions corresponding to the top pair ofopposed side portions, such that the top and bottom pairs of opposedside portions mate with each other to define the pair of opposed sidemembers. Also included is a plurality of insert members disposed betweentop and bottom pairs of opposed side portions for enhancing the strengthof the top frame assembly. The inserts are preferably metallic andplanar. The top member includes a top surface and the bottom memberincludes a bottom surface, such that the top and bottom surfaces areeach planar and oriented parallel to each other. The top pair of opposedside portions include a first mating surface, and the bottom pair ofopposed side portions include a second mating surface, such that atleast one of the first and second mating surface is defined by a ribpattern, which may be a cross-rib pattern.

[0014] The first and second mating surfaces are attached to each othersuch that the mating surfaces define a plurality of whole box beamsections extending across the top frame assembly. In this embodiment,the top member may have a generally rectangular top perimeter memberwhich includes the top pair of opposed side portions, and the bottommember may have a corresponding generally rectangular bottom perimetermember which includes the bottom pair of opposed side portions, and suchthat the top perimeter member includes a first mating surface and thebottom perimeter member includes a second mating surface for attachingto the first mating surface.

[0015] Provided according to the present invention is another top frameassembly which includes a first member having a planar first matingsurface, a second member which has a planar second mating surfaceattached to the first mating surface, and at least one insert memberhaving a planar portion and is disposed between the first and secondmembers and oriented generally parallel to the first and second matingsurfaces. Preferably, the insert is a metallic insert. The first membermay have a first pair of opposed side members including the first matingsurface, and the bottom member may have a corresponding second pair ofopposed side members which includes the second mating surface, such thatthe at least one planar insert is a pair of inserts each of which isdisposed between a respective first and second pair of opposed sidemembers. The first member includes a first outer surface and the secondmember includes a second outer surface, such that the first and secondouter surfaces are each planar and oriented parallel to each other.Also, at least one of the first and second mating surfaces may bedefined by a rib pattern, and may include a cross-ribbing pattern. Stillfurther, the first and second mating surfaces are attached to each othersuch that the mating surfaces define a plurality of whole box beamsections extending across the top frame assembly. Still further, thefirst member has a generally rectangular first perimeter member whichincludes the first mating surface, and the second member has a generallyrectangular second perimeter member which corresponds to the firstperimeter member, and where the second perimeter member including thesecond mating surface.

[0016] Also provided in accordance with the present invention is a topframe assembly having an upper frame portion having a generallyrectangular upper perimeter member with a first mating surface, a lowerframe portion having generally rectangular lower perimeter membercorresponding to the upper perimeter member, the lower perimeter memberhaving a second mating surface attached to the first mating surface.Also included is a plurality of planar insert members disposed betweenthe first and second mating surfaces for enhancing the strength of thetop frame assembly. The upper perimeter member has a first pair ofopposed side members including the first mating surface, and the lowerperimeter member has a corresponding second pair of opposed side membersincluding the second mating surface, such that each of the plurality ofinserts is disposed between a respective first and second pair ofopposed side members. The upper perimeter member may also include afirst outer surface, and the lower perimeter member may include a secondouter surface, such that the first and second outer surfaces are eachplanar and oriented parallel to each other. One of the first and secondmating surfaces may be defined by a rib pattern. The first and secondmating surfaces are attached to each other such that the rib patterndefines a plurality of whole box beam sections extending across the topframe assembly.

[0017] The above objects and other objects, features, and advantages ofthe present invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0018]FIG. 1 is a perspective view of the top frame assembly accordingto the present invention;

[0019]FIG. 2 is a top plan view of the top frame of FIGS. 1-3, thebottom plan view being a mirror image thereof;

[0020]FIG. 3a is an exploded perspective assembly view of the top frameassembly according to the present invention and particularly illustratesan insert between the upper and lower top frame members according to thepresent invention;

[0021]FIG. 3b is a perspective view of one top frame portion accordingto the present invention having a plurality of inserts disposed thereon;and

[0022]FIG. 4a is an exploded, enlarged, partial perspective view of thebottom member of the top frame shown in FIG. 4a having the firstembodiment of the insert separated therefrom;

[0023]FIG. 4b is an enlarged, partial perspective view of the bottommember of the top frame assembly having the first embodiment of theinsert positioned thereon;

[0024]FIG. 5a is a partial cross-sectional view of the top frameassembly taken along line A-A of FIG. 3b, illustrating the firstembodiment of the insert member shown in FIGS. 3a-3 b;

[0025]FIG. 5b is a full cross-sectional view of the top frame assemblyshown in FIG. 5a, taken along the line B-B of FIG. 2;

[0026]FIG. 6a is a partial cross-sectional view of the top frameassembly similar to that of FIG. 5, illustrating a second embodiment ofthe insert member;

[0027]FIG. 6b is a full cross-sectional view of the top frame assemblysimilar to that of FIG. 6a with the second embodiment;

[0028]FIG. 7a is a partial cross-sectional view of the top frameassembly similar to that of FIG. 5, illustrating a third embodiment ofthe insert member;

[0029]FIG. 7b is a full cross-sectional view of the top frame assemblysimilar to that of FIG. 7a with the third embodiment;

[0030]FIG. 8a is a cross-sectional view of the top frame assemblysimilar to that of FIG. 5, illustrating a fourth embodiment of theinsert member;

[0031]FIG. 8b is a full cross-sectional view of the top frame assemblysimilar to that of FIG. 8a with the fourth embodiment;

[0032]FIG. 9 is a partial cross-sectional perspective view of the bottommember of the top frame assembly showing adjacent side and end members,each having an insert member disposed thereon;

[0033]FIG. 10 is another partial cross-sectional perspective view of thebottom member of the top frame assembly showing adjacent side and endmembers similar to FIG. 9, the end members having a vertically orientedinsert and the side members having a horizontally oriented insert;

[0034]FIG. 11 illustrates a partial cross-sectional view of the topframe assembly taken along line C-C of FIG. 3b through the hole of theinsert member, illustrating the first embodiment of the insert membershown in FIGS. 3a-3 b;

[0035]FIG. 12 is a perspective cross-sectional view of a side of the topframe assembly which does not include an insert member disposed betweenthe upper and lower top frame members, taken along line D-D of FIG. 2;

[0036]FIGS. 13a-f illustrate the method according to the presentinvention of forming and assembling the top frame assembly;

[0037]FIG. 14 is a side elevational view of a top frame assembly in usein conjunction with a pallet, and having layers of objects with slipsheets disposed therebetween;

[0038]FIG. 15a is a perspective view of another embodiment of the topframe assembly according to the present invention;

[0039]FIG. 15b is a cross-sectional view taken along line E-E of FIG.15a;

[0040]FIG. 16a is a perspective view of still another embodiment of thetop frame assembly according to the present invention;

[0041]FIG. 16b is a cross-sectional view taken along line F-F of FIG.16a;

[0042]FIG. 17a is a perspective view of yet another embodiment of thetop frame assembly according to the present invention;

[0043]FIG. 17b is a cross-sectional view taken along line G-G of FIG.17a;

[0044]FIG. 18a is a perspective view of another embodiment of the topframe assembly according to the present invention having a cross-membertherein; and

[0045]FIG. 18b is a cross-sectional view taken along line H-H of FIG.18a.

BEST MODE FOR CARRYING OUT THE INVENTION

[0046] Disclosed herein is a top frame assembly 10 according to thepresent invention, illustrated in FIGS. 1-3. FIG. 1 illustrates aperspective view of top frame assembly 10. Top frame 10 is preferablyformed of a thermoplastic or other polymeric material and is alsopreferably, but not necessarily, formed by an injection molding process.Top frame 10 is shown in FIGS. 1-3 as having a generally rectangularshape and also as being generally symmetrical about each centerline.However, it is fully contemplated that top frame assembly 10 may havevarious shapes and configurations without departing from the teachingsaccording to the present invention. For example, top frame assembly 10may also include one or more members or cross-members extending acrosscentral opening 26 (as illustrated in FIG. 18a.) FIG. 2 illustrates atop plan view of top frame assembly 10.

[0047] As best illustrated in the exploded perspective view of FIG. 3a,top frame assembly 10 includes an upper (first, top) member 12 and alower (second, bottom) member 14 which correspond to and mate with eachother. Particularly, as illustrated in FIGS. 2, 3a and 5 b, upper member12 has a flat, planar upper surface 16, and also includes a lower (firstmating) surface 18. Lower member 14, on the other hand, includes aplanar lower surface 20 and also includes an upper (second mating)surface 22. With further reference to FIG. 5b, mating lower surface 18of upper member 12 mates with and attaches to corresponding uppersurface 22 of bottom member 14. More particularly, planar mating surface18 of upper member 12 is generally defined by outer edge 19 which is adownwardly projecting flange member which extends around the perimeterof upper member 12, and also by inner edge 21 which is also a downwardlyprojecting flange member which extends around the interior of uppermember 12 and helps define opening 26. As shown in FIGS. 5b, 6 b, 7 b, 8b, upper member 12 may also include ribs 24 which generally correspondto and mirror those ribs 25 of bottom member 14 shown in FIGS. 3a and 3b and which are also generally co-planar with outer and inner edges19,21.

[0048] With regard to lower member 14, planar mating surface 22 of lowermember 14 is generally defined by outer edge 29, which is an upwardlyprojecting flange member 29 (which extends around the perimeter of lowermember 14 and corresponds to upper mating flange 19), and is alsodefined by inner edge 31 which extends around the interior of lowermember 14 and corresponds to mating flange 21. Those ribs 27 disposedbelow insert members 80 are generally not co-planar with edges 29,31, asshown in FIGS. 5a, 6 a, 7 a, 8 a. However, ribs 25 in corner portions 35which do not have an insert member according to the present inventionmay be fully co-planar with edges 29,31. Ribs 25 and 27 may of courseinclude cross-ribbing as shown in FIGS. 3a-3 b. Also, it is fullycontemplated that one of upper member 12 and bottom member 14 may have aribbing pattern, including cross-ribbing, while the other may include amating surface 18,22 which is planar sheet of plastic without ribs whichis welded or attached to the opposed mating surface.

[0049] With reference to FIG. 1, in the embodiment illustrated, topframe assembly 10 has a central opening 26 defined by an outer rail 28,which includes a first pair of opposed side members 30,32 and a secondpair of opposed side members 34,36. For ease of reference, the firstpair of side members may be referred to as side members 30,32, while thesecond pair of opposed side members may be referred to as end members34,36. Referring again to FIGS. 3a and 3 b, side member 30 is defined byupper side member 38 and lower side member 40. Side member 32 is definedby upper side member 42 and lower side member 44. End member 34 isdefined by upper end member 46 and lower end member 48. End member 36 isdefined by upper end member 50 and lower end member 52.

[0050] Further, with reference to FIG. 1, side members 30,32respectively include a first pair of opposed outer edges 54,56 (sideedges), while end members 34,36 respectively include a second pair ofopposed outer edges 58,60 (end edges). Referring again to FIGS. 2, 3aand 3 b, edge 54 is defined by upper member and lower member edges62,64, respectively. Edge 56 is defined by upper member and lower memberedges 66,68, respectively. Edge 58 is defined by upper member and lowermember edges 70,72, respectively. Edge 60 is defined by upper member andlower member edges 74,76, respectively. Upon welding or fasteningmembers 12,14 together according to the present invention, a partingline 78 results between the respective mating edges. (See FIG. 1.) Outeredge 19 of upper member 12 includes edge portions 62, 66, 70, and 74,while outer edge portion 29 of lower member 14 includes edge portions64, 68, 72, and 76.

[0051] As illustrated in FIGS. 3a, 3 b, 4 a, 4 b, 5 a, and 5 b and inaccordance with the present invention, top frame assembly 10 alsoincludes at least one, but preferably a plurality, of insert members 80which provide and enhance the strength, reinforcement, and stiffnessproperties of top frame assembly 10 (see also the other embodiments ofthe insert member illustrated in FIGS. 6a, 6 b, 7 a, 7 b, 8 a, and 8 b.)As illustrated in FIGS. 3a-3 b, a pair of elongated, longitudinallyextending insert members 80 are shown disposed in a generally planarorientation between upper member 12 and bottom member 14 such that it issandwiched between both mating surfaces 18,22 and generally parallelthereto. For example, as illustrated in FIGS. 3a-3 b, insert member 80is positioned between each corresponding pair of rail upper and lowerside members 38,40 and 42,44.

[0052] Insert member 80 is preferably formed of metal, but may be alsoformed of composite or structural plastic, or any other materialproviding the desired properties. In one embodiment of a rectangular topframe assembly 10 which is 56 inches long, 44 inches wide and 1.5 inchesdeep, insert 80 centrally disposed within side members 30,32 and is 52inches long, 3.5 inches wide, and 0.025 inches thick. With reference toFIGS. 3a and 3 b, insert 80 is illustrated as extending along the lengthof each of the side members 32,34 (and positioned between slide members38,40 and 42,44) whereas no insert is shown along the end members 34,36(or between end members 46,48 and 50,52.) Also, while no portion ofinsert member is shown extending into the corner areas 35, in otherembodiments it may extend across top frame assembly 10 and into thecorner areas. Prior to attaching upper member 12 and lower member 14,insert member 80 extends widthwise between outer edge 29 and inner edge31 of lower frame member 14.

[0053] Thus, after insert member 80 or plurality of insert members 80are positioned on the desired side rails of either the upper or lowermember (12 or 14), the members 12,14 are heated and introduced to eachother as described herein in association with FIGS. 13a-13 f. Note thatinsert members 80 are illustrated as being generally solid andcontinuous, except for a plurality of holes 82 and notches 84 formedtherein. Because of the generally solid and continuous nature of insertmembers 80, the majority of the inner rib pattern or structure of thoseportions of rail 28 which are covered by insert 20 are therefore notable to mate with the corresponding rib structure. For example, in FIGS.3a and 4 a, the ribs along lower side members 40, 44 (such as pluralitypattern of ribs 79 and 81) are covered by insert member 80 and thus theywill not mate with or weld with the corresponding mating ribs 24 ofupper side members 38,42, respectively (see also FIGS. 5b, 6 b, 7 b, and8 b.) In those areas, the welding takes place along side members 30,32,by way of welding together upper and lower outer edges 19,21, and alsothe co-planar upper and lower inner edges 29,3. In areas having insertmember 80 disposed therebetween, the welding or attachment may also takeplace through portions of ribs 25 which are exposed through holes 82 andnotches 84 in insert member 80, and thus are able to mate and be weldedtogether in these areas for greater surface area attachment betweenupper and lower members 12,14 (best shown in the cross-sectional view ofFIG. 10 taken through hole 82 in insert 80, and also shown in FIG. 4b.)

[0054]FIG. 5a is an enlarged, partial cross-sectional view of the bottommember of the top frame assembly having the first embodiment of planar,flat insert member 80 positioned thereon, taken along line A-A of FIG.3b. FIG. 5b is a cross-sectional view of the top frame assembly takenalong line B-B of FIG. 2, illustrating the first embodiment of theinsert member shown in FIGS. 3a, 3 b, 4 a, and 4 b.

[0055]FIGS. 6a, 6 b, 7 a, 7 b, 8 a and 8 b and 8-10 illustrate othervarious possible designs and embodiments of the. insert member accordingto the present invention. Of course, the various insert memberembodiments are illustrated by way of example and not limitation, as theinsert member disclosed herein may have any number of designs andconfigurations, the selection of which may be chosen based on thedesired use, application, and properties of the top frame assembly.

[0056]FIG. 6a is a partial cross-sectional view of the top frameassembly similar to that of FIG. 5a, illustrating a second embodiment ofthe insert member 90 positioned upon side member 30 of rail 28. Asillustrated in FIGS. 6a-6 b, insert member 90 is shaped like a “T”,having a flat planar portion 92 and a second planar portion 94 orientedperpendicular thereto, thus having portions 96,98 extending into uppermember 12 and lower member 14, adjacent inner walls 21, 31. FIG. 6b is aview similar to that of FIG. 5b.

[0057]FIG. 7a is a cross-sectional view of the top frame assemblysimilar to that of FIG. 5, illustrating a third embodiment of the insertmember 100. FIG. 7b is a cross-sectional view of the top frame assemblysimilar to that of FIG. 5b, illustrating insert member 100. Asillustrated in FIGS. 7a-7 b, from outer wall 21, insert member 100extends inwardly and has a flat planar portion 102 which transitionsinto an angled portion 104 extending into upper member 12, and then hasan end portion 106 which extends downwardly at 90° within lower member14, proximate inner wall 31.

[0058]FIG. 8a-8 b are other partial cross-sectional views of top frameassembly 10 similar to that of FIGS. 5a and 5 b, illustrating a fourthembodiment of the insert member 110. As shown therein, has a flat planarportion 112, and an end portion 114 extending perpendicular theretotoward one of the upper member 12 and lower member 14, and particularlyshown oriented in a downward orientation.

[0059] In another embodiment according to the present invention, insertmembers according to the present invention are located on each of theside and end members 40, 44, 48, and 52 of bottom member 14 of top frameassembly 10, as shown in the partial cross-sectional view in FIG. 9 ofthe symmetrical top frame assembly. As illustrated therein, an insertmember 80 is disposed on each of the side members 40,44 and end members48,52 for providing strength and resistance against deformation andbuckling along each side.

[0060] In yet another embodiment shown in FIG. 10, side member 40 ofbottom top frame member 14 includes an insert member 80 extendingthereacross, as previously shown and described in association with FIGS.3a and 3 b. Moreover, end member 48 includes a vertically orientedinsert member 120 (which, with reference to FIGS. 6a-6 b, is similar tothe vertically oriented portions 96,98 of insert member 90, but does nothave flat planar portion 92.) In a rectangular top frame, the longerside members 30,32 may tend to deflect inward horizontally, or in aplane parallel to the insert member 80 or top surface 16. Therefore,planar insert members 80, or those substantially planar such as insertmembers 90, 100, 110, may be used to provide strength and reinforcementin this direction. On the other hand, the shorter end members 34,36 maytend to bow or buckle under load (strapping forces), causing deflectionin the vertical direction, or away from horizontal. Thus verticallyoriented insert member 120 may be used to provide strength andreinforcement in those directions. In the embodiment of a top frameassembly 10 which is 56 inches long, 44 inches wide and 1.5 inches deep,insert member 120 may be 1.0 inch tall, 0.025 inch thick, and 40 incheslong.

[0061] As shown in FIGS. 6a-b, 7 a-b, and 10, a portion of verticalinsert members 90, 100, and 120 may extend above planar surface 22.Thus, if a hot plate welding process is used to assemble this top frameassembly as illustrated in FIGS. 13a-f, a groove maybe formed within theplaten 326 to accommodate such upwardly extending portions of thevarious insert members.

[0062] Of course, it is fully contemplated that the insert members arenot limited to those designs shown, but may have any shape or design infurtherance of the teachings according to the present invention. Also,any of the insert members disclosed and shown herein according to thepresent invention may be used in any area of top frame assembly 10 toprovide the desired reinforcement, and are not limited to placement inthose areas or top frame members disclosed. For example, any of theinsert members may be used as desired to reinforce one or more of sideand end members 30,32,34, and 36. In addition, should top frame assemblyhave members or cross-members extending across opening 26, those membersmay also include insert members for reinforcement according to thepresent invention, as illustrated in FIGS. 18a-b. Further as illustratedin FIGS. 15-17, the teachings according to the present invention are notlimited to two piece top frames which have an insert and are weldedtogether, but may include any top frame having a reinforcing insert asdisclosed and taught herein.

[0063] With reference to the cross-sectional views of FIGS. 5a, 6 a, 7a, and 8 a, it is noted that the ribs 27, 81, 79 upon which the insertmembers rest have a lower height than the adjacent portions of outer andinner edges 29,31, respectively (i.e. below surface plane 22). Thisallows the insert members 80 to be securely positioned within lowermember 14 below planar surface 22, prior to the welding processdiscussed below. As illustrated in FIGS. 5b, 6 b, 7 b and 8 b, thisallows the portions of edges 29,31 and ribs 25 to be plasticized duringthe welding process as disclosed further herein. In the otherembodiments of insert members 90, 100, and 110, the lower profile ribportions 27 disposed below the insert members allow the relatively largeflat, planar portion (92, 102, and 112) of these insert members to besecurely positioned therein. As shown in FIGS. 5b, 6 b, 7 b and 8 b,after welding, the insert is preferably co-planar with the parting line78, but of course may vary due to welding and build variations.

[0064] According to the present invention, top frame members 12,14 arepreferably fastened to each other by a hot plate welding operation,known in the art. (See FIGS. 13a-13 f.) In these portions withoutinserts, the corresponding ribs on both members 12,14 are aligned sothey preferably are welded together by plasticizing their matingsurfaces to form box-beam sections, resulting in a top frame assemblywhere every section without an insert has a box beam. Note that theorder of the plasticizing procedure is provided for illustrativepurposes only, and of course, such steps may be performed in anyfeasible order. Also the plasticizing process for the top frame may alsobe accomplished by infrared radiation or another process designed toprovide the desired properties of top frame 10.

[0065] Attention is directed to the method of assembling top frameassembly 10 according to the present invention. The preferredmanufacturing assembly process is by the hot plate welding process whichis best illustrated in FIGS. 13a-13 f of the drawings. As indicatedabove, however, any suitable fastening means may be used such as, forexample, infrared radiation, epoxy, etc. The hot plate welding processmay be characterized as either contact hot plate welding or non-contacthot plate welding. This process should provide weld strength propertiesand produce seals between the mating (welded) components as strong asthose of the parent polymer. According to the present invention, the topframe mating surfaces, are either placed in contact (in the contact hotplate welding process) or closely approach (in the non-contactvariation) a heated platen 156 (preferably formed of steel) or similartool in order to create a molten or plasticized region on the matingsurfaces. Platen 156 is then moved out of the way and the plasticizedregions are then pressed together to form the weld.

[0066] As illustrated in FIG. 13a, more particularly, in practice, theprocess is operated on a hot plate welding machine 150 (known in theart) in which the corresponding top frame 12,14 members which are to bewelded together are securely attached by clamping in holding fixtures152 and 154. With reference to FIG. 13b, platen 156 of welding machine150 is heated to a predetermined temperature and is extended between theseparated upper member 12 and bottom member 14. Holding fixtures 152 and154 are moved toward each other and toward platen 156, whereupon theweld planes of top frame members 12,14 are either pressed against platen156 (by the contact version using conducted heat) or are moved closelyto platen 156 (by the non-contact version using radiant heat.) Thechoice of which method to use is dependant on many factors including theproperties of the materials to be welded; cycle times required; size anddesign of the component; accuracy and repeatability of the weldingmachine; and use of the welded component.

[0067] In the contact hot plate welding process, heat is conducted byway of physical contact of members 12,14 to be welded with heated platen156 (FIG. 13c). Further, the surface of each mating surface 18,22 isplasticized or melted until contact is complete (referred to in the artas “matching”). At this point, further platen 156 movement is oftenhalted, and heating is continued, in order to create a deeper (to apredetermined depth), and relatively more molten, plasticized zone inwhich material is displaced. In the non-contact process, FIG. 13c isdisregarded and surfaces 18,22 do not contact platen 156, but insteadradiant heat is applied to the parts to be welded which is generated byholding the parts to be welded very close to the heated platen (targetplates) and allowing them to heat over time.

[0068] With reference to FIG. 13d, for either version, after apredetermined period of time, heating is complete and the surfacemelting has reached a predetermined melt depth, the parts are retractedfrom platen 156. Platen 156 is then moved out of the way, whereupon theadjoining top frame members 12,14 are forged together and held for apredetermined period of time until the plasticized material isstabilized and the mating surfaces cools. (See FIG. 13e.) Mechanical ormicroprocessor-controlled stops may be used to control the amount ofmaterial displacement of the top frame polymer from the weld zone,particularly during the heating phase. Finally, with reference to FIG.13f, fixtures 152 and 154 are separated to their part loading positionand welded top frame assembly 10 with insert contained therein, is heldto one of the fixtures (shown in FIG. 13f as fixture 154) for unloading.The part is then removed from welding machine 150.

[0069] Weld times to form top frame assembly 10 may vary with the volumeof polymer to be fused and the thermal conductivity of the respectivetop frame member. Accordingly, welding times for top frame assembly 10may fall in the range from 5 to 60 seconds, although the mass of topframe members to be plasticized, the size and quantity of the insertmembers, and the corresponding cooling rates will govern cycle times.The size of top frame assembly 10 that may be hot plate welded accordingto the present invention is limited only by the practical size ofholding fixtures 152 and 154 and platen 156 of welding machine 150, andalso of the mechanics of the removal of the welded assembly orsubassembly from the weld zone and moving top frame assembly 10components for forging them together.

[0070] Each of the contact and non-contact methods have theiradvantages, including: in the non-contact method, no special coating onplaten 156 is required for material release, no residue builds-up onplaten 156, there is no loss of weld edge material against heated platen156 and finished parts have consistent weld characteristics. Whereas,the advantages of contact heating are a quicker cycle time, lowertemperature required for platen 156, the method is more tolerant oflarger design components, such as top frame assembly 10 disclosedherein, and also more tolerant of less dimensionally consistentcomponents.

[0071] Welding top frame assembly 10 as described herein with insert 80provides a high strength weld suitable for parts operating underpressure. The parting line 78 is relatively inconspicuous. Further, noother attachment methods, such as adhesives, solvents, mechanicalfasteners such as nails or staples, are required. Also, complex shapesare capable of being welded since there is no relative motion requiredin the welding process.

[0072] Another assembly process known as infrared radiation may also beused as a non-contact alternative to hot plate welding for use informing and assembling top frame assembly 10 according to the presentinvention. In such a process, the infrared radiation is often suppliedby high intensity, quartz heat lamps which produce radiation havingwavelengths of around one micron. As with hot plate welding, when thisradiation is applied to mating surfaces 18,22 of top frame assembly 10,plasticization of the surfaces occurs. In one application, radiationsource, such as heat lamps, are removed after melting has occurred andthe parts are forged together just as with the platen in hot platewelding. Infrared welding tends to melt the zone relatively quickly. Hotplate welding uses conduction to create the necessary plasticized zone.Of course, as with any other process, the depth of penetration of theplasticization depends on many factors and it varies strongly with onlyminor changes in polymer formulation.

[0073] As noted above, ribs 27, 79, 81 disposed below the correspondinginsert members have a lower profile creating a pocket into which theinsert member may be positioned prior to the above welding processes.However, it is also contemplated that ribs 27, 79, 81 upon which insert80 rests, may be co-planar with edges 29,31 to assist in defining planarsurface 22. In this design, when the respective ribs 24,27 above andbelow the insert members 80 are plasticized, the upper and lower members12,14 are held together for bonding, and the insert member displaces theplasticized material in those regions, thereby fitting between upper andlower members 12,14, and also allowing for additional bonding betweenthe plasticized top frame plastic and the metal insert member.

[0074]FIG. 14 shows a top frame assembly in operation. As illustratedtherein, top frame assembly 10 according to the present invention ispositioned upon a plurality of layers of objects for transport andstorage, which are stacked upon a pallet. Such objects are shown in FIG.14 as a plurality of empty bottles 316, but of course may be any ofvarious objects which may be transported by and stored on pallet and towhich the teachings according to the present invention apply, includingcans. A first layer of bottles 316 is loaded on pallet 310. Typically, aplanar member 318 is positioned on the upper surface of bottles 316.Planar member 318 may be referred to as a slip sheet in the art, and istypically formed of cardboard or fiberboard. As illustrated, anotherlayer of bottles 316 maybe disposed on top of planar member 318, andthen another planar member 318 is positioned on top of that layer ofbottles 316.

[0075] This procedure is repeated for as many layers as is practical anddesired, for example the eight layers of bottles shown in FIG. 14. Afterthe final planar member is positioned, top frame assembly 10 ispositioned on top of the planar member so that the product issandwiched. Pallet 310 and top frame assembly 10, with the objectsdisposed therebetween, are strapped together via straps 320. As shown inFIGS. 1 and 2, top frame assembly 10 has recesses 86 and chamfered edges87,89 around its sides in which straps 320 are positioned so that theydo not move or easily slide off of the outer rail 28 during shipment.Subsequently, the resulting packaging (as shown in FIG. 14) is typicallycovered and protected, such as by applying a shrink plastic wrap.Opening 26 of top frame assembly 10 assists in lowering the weight oftop frame assembly 10 while the disclosed insert members 80 and box-beamsections provide the desired strength and rigidity to top frame 10.

[0076]FIG. 12 illustrates that fastening together, or welding, each ofthe above respective pairs of ribs which are aligned define box-beamsection walls of top frame 10, in those areas of top frame assembly 10which do not include an insert member 80. FIG. 12 is a perspective viewshown as taken along line D-D of FIG. 2. Thus, in embodiments where aportion of the top frame assembly does not include an insert member 80,top frame assembly 10 includes box beam sections 77 (best shown in FIG.12) formed between top member 12 and bottom member 14 as illustrated inFIG. 12, in areas where no insert member 80 is located, such as thecorner portions shown in FIGS. 3a, 3 b, for example. In these non-insertareas, top frame assembly 10 also includes mating planar surfaces 18 and22 which when fastened according to the teachings of the presentinvention define box beam sections therein as well as the parting line78 between upper member 12 and bottom member 14. Top frame assembly 10also includes one or more holes 88 extending therethrough for receivinga grommet (not shown) therein for providing skid or slip resistance whenstacking top frames.

[0077] Top frame 10 thus provides greater load stability andreinforcement which allows the objects 216 to be stacked higher and withgreater stability. Further, with top frame 10 positioned and secured ontop of the stack, it is contemplated that another pallet, such as pallet210, may be stacked on top of top frame 10. The metal insert members 80,90, 100, 110, included within top frame assembly 10 provide improvedstiffness, reinforcement, and strength to the part and minimize anybowing or flexing of the part, and also to minimize or prevent anydeformation that would result from applying straps 320 to a prior artplastic or wood top frame.

[0078] FIGS. 15-16 illustrate another embodiment according to thepresent invention. FIG. 15a illustrates a top frame assembly 170according to the present invention which has a frame 178 formed ofplastic and preferably formed by an extrusion process. Top frame 178 hasa removable corner portion 171 which is preferably formed of injectionmolded plastic and covers the open ends 176 of each side portion 174.One or more ribs 172 is shown extending down each side portion 174 oftop frame assembly 170 from top surface 173 to bottom surface 175,dividing side portion 174 into a plurality of cavities 177, 179. Asillustrated in the cross-sectional view of FIG. 15b taken along the lineE-E of FIG. 15a, an insert member 100′ (shown as similar to insertmember 100) is inserted into one of the cavities (shown as cavity 177)from open end 176 and preferably extends along the length of side member174. Of course, an insert member may be received by the other cavity orboth cavities without departing from the teachings herein. Further, aninsert member may be received by any or all of side members 174.

[0079]FIG. 16a illustrates yet another embodiment of a top frameassembly 180 according to the present invention, similar to that of FIG.15a. Top frame 188 is formed of plastic and is preferably formed by anextrusion or blow molding process, in order to define hollow cavity 185.Alternatively, any or all of the wall members which form each sideportion 184 may be molded separately and welded together. As illustratedin the cross-sectional view of FIG. 16b taken along line F-F of FIG.16a, an insert member (for example insert member 100) is inserted intocavity 187 from open end 186 and preferably extends along the length ofone or more side members 184. Top frame assembly also has a top surface183 and a bottom surface 185.

[0080]FIG. 17a illustrates yet another embodiment of a top frameassembly 190 according to the present invention. Top frame 198 is formedof plastic by an extrusion process. The corners are then cut at theappropriate angles and attached or welded together. Prior to welding theframe side portions 194 together, an insert member is inserted therein,as illustrated in the cross-sectional view of FIG. 17b, taken along theline G-G in FIG. 17a, in which an insert member 100′ is received by atleast one of the cavity portions 200, 201, 202 and 203.

[0081]FIG. 18a illustrates still another embodiment of a top frameassembly 210 according to the present invention. Top frame assembly 210is similar to top frame assembly 10 previously disclosed, with theaddition of a cross-member 211. Features similar to that of top frameassembly 10 have a corresponding reference number with the addition of a“2” prefix. As shown in the cross-sectional view of FIG. 18b, takenalong lines H-H of FIG. 18b, the cross member 211 may be reinforcedsimilar to the side and end rails, previously disclosed. Of course, anyof the top frame embodiments disclosed herein may include cross membersof any design or configuration.

[0082] While embodiments of the invention have been illustrated anddescribed, it is not intended that these embodiments illustrate anddescribe all possible forms of the invention. Rather, the words used inthe specification are words of description rather than limitation, andit is understood that various changes may be made without departing fromthe spirit and scope of the invention.

What is claimed is:
 1. A top frame assembly comprising: an upper memberhaving a central opening defined therethrough, the upper member having agenerally planar upper wall, a first plurality of ribs extendingdownwardly therefrom, and a first mating surface; and a bottom memberhaving a central opening defined therethrough, the bottom member havinga generally planar lower wall, a second plurality of ribs extendingupwardly therefrom, and a second mating surface, wherein the first andsecond mating surfaces are attached to each other; and at least oneinsert member disposed between the upper wall and the lower wall forproviding strength thereto.
 2. The top frame assembly of claim 1 whereinthe top frame assembly has a generally rectangular perimeter at leastsubstantially circumscribing the central opening, wherein the at leastone insert member extends along at least one side of the generallyrectangular perimeter.
 3. The top frame assembly of claim 1, wherein thetop frame assembly has a generally rectangular perimeter at leastsubstantially circumscribing the central opening.
 4. The top frameassembly of claim 1 wherein the at least one insert member is elongatedand is at least substantially parallel to the upper wall and the lowerwall.
 5. The top frame assembly of claim 4 wherein the at least oneinsert member is at least substantially planar.
 6. A top frame assemblycomprising: a first member having a first outer surface and a firstmating surface spaced apart from each other by at least one rib, thefirst outer surface defining a central opening; a second member having asecond outer surface and a second mating surface, the second matingsurface mating with the first mating surface, the second outer surfacedefining a central opening; and at least one reinforcement memberbetween the first outer surface and the second outer surface forreinforcing the top frame assembly.
 7. The top frame assembly of claim 6wherein the at least one reinforcement member is a metal insert.
 8. Thetop frame assembly of claim 6 wherein the at least one reinforcementmember includes a planar portion.
 9. The top frame assembly of claim 6wherein the first member has a first pair of opposed side members oneither side of the central opening, and the second member has acorresponding second pair of opposed side members on either side of thecentral opening, wherein the at least one reinforcement member is a pairof reinforcement members each of which is disposed between one of thefirst pair of opposed side members and one of the second pair of opposedside members.
 10. The top frame assembly of claim 6 wherein the topframe assembly is on top of at least one object on a pallet, the topframe assembly secured to the pallet.
 11. The top frame assembly ofclaim 6 wherein at least one of the first and second mating surfacesincludes a plurality of ribs.
 12. The top frame assembly of claim 11wherein the first and second mating surfaces are attached to each othersuch that rib patterns on each of the first and second mating surfacesdefines a plurality of box beam sections extending across a portion ofthe top frame assembly.
 13. The top frame assembly of claim 6 whereinthe first member has a generally rectangular first perimeter memberwhich includes the first mating surface, and wherein the second memberhas a generally rectangular second perimeter member which corresponds tothe first perimeter member, the second perimeter member including thesecond mating surface.
 14. A top frame assembly comprising: a firstmember having a substantially flat first outer wall and a first matingsurface defined by a first outer flange; a second member having asubstantially flat second outer wall and a second mating surface definedby a second outer flange for attaching to the first mating surface, thefirst and second members defining a central opening through the topframe assembly, the first and second walls spaced apart and orientedsubstantially parallel to each other; and at least one insert memberdisposed between the first and second members for enhancing the strengthof the top frame assembly.
 15. The top frame assembly of claim 14wherein the at least one insert member is metal.
 16. The top frameassembly of claim 15 wherein the first member and the second member areeach molded plastic.
 17. The top frame assembly of claim 14 wherein thefirst member has a generally rectangular first perimeter member whichincludes the first mating surface, and wherein the second member has agenerally rectangular second perimeter member which corresponds to thefirst perimeter member, the second perimeter member including the secondmating surface.
 18. The top frame assembly of claim 14 wherein the topframe assembly is on top of at least one object on a pallet, the topframe assembly secured to the pallet.
 19. The top frame assembly ofclaim 14 wherein the first and second members each comprise an outer,generally rectangular, peripheral rail defining a central opening. 20.The top frame assembly of claim 14 wherein the at least one insertmember includes a plurality of metal inserts.